Vertically rotating grooming attachment brush and method of use

ABSTRACT

A vertically rotating grooming attachment brush comprising a brush hub and bristles, and method for cleaning a surface having organic biofouling. The bristles extend from the brush hub and are positioned at or near its outer rim. One or more rows of bristles can be included. The bristles can be grooming bristles or shroud bristles or a combination of the two. A rigid or elastomeric shroud or skirt can also be included about the edge of the brush hub. Vertical rotation of the grooming attachment brush causes a low pressure region to build in the central area of the brush hub. This low pressure region creates a force that forcefully attracts the grooming attachment brush to the surface to be cleaned.

CROSS REFERENCE TO RELATED APPLICATIONS AND INCORPORATION BY REFERENCE

This non-provisional patent application filed under 35 U.S.C. 111(a) claims the benefit of U.S. provisional patent application Ser. No. 62/045,711 filed in the United States Patent and Trademark Office (USPTO) on Sep. 4, 2014, which is herein incorporated by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under contract number N00014-10-1-0919 (Advanced Nontoxic Anti-Fouling Coatings Research, Test Site Facility) awarded by the Office of Naval Research and contract number N00014-11-1-0915 (Large Scale Seawater Facility for Development of Hullbug) awarded by the Office of Naval Research. The Government has certain rights in this invention.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure generally relates to ship hull grooming; more specifically, to a grooming attachment brush for use in ship hull grooming and a method of using a grooming attachment brush for grooming, or cleaning, a surface to be cleaned. The surface to be cleaned may be, for example and not by way of limitation, a surface of a hull of a ship having biofouling.

2. Background

Navy ships spend a significant amount of time at port and accumulate biofouling that increases the ship's drag and fuel consumption. One of the current practices is to wait until hard fouling becomes established and to remove the fouling from the hull by diver-operated cleaning vehicles. These use stiff brushes that may damage the ship's coating. A proactive approach to controlling fouling, called grooming, is also used. Grooming utilizes softer brushes and cleans the surfaces of ship hulls at a frequency that removes fouling before larger organisms, which may cause hard fouling, become established.

An autonomous underwater vehicle (described in U.S. Pat. No. 8,506,719 to Holappa et al.) called HULL BUG™ has been designed to implement the grooming process. The vehicle attaches to the hull by a low pressure region generated by a semi-closed impeller (described in U.S. Pat. No. 6,497,553 to Illingworth et al.) and has a separate grooming tool comprised of vertically rotating brushes.

There are also commercial cleaning vehicles currently available on the market (described in U.S. Pat. Nos. 3,906,572; 5,947,051; 8,393,421; 6,886,486). All of these designs attach the vehicle to a surface by the use of an open impeller or a magnet.

A commercial cleaner (described in U.S. Pat. No. 6,209,473 to Jones) utilizes the negative pressure generated by its rotating brushes to attach itself to a surface; however, the attachment force provided by the design is low.

What is needed in the art, therefore, is an apparatus adapted to attach itself to a surface to be cleaned, or groomed, that attaches with a high enough attractive force to effectively groom or clean a surface such as a surface of a ship hull having biofouling.

BRIEF SUMMARY OF THE INVENTION

The present invention comprises an apparatus and method that have one or more of the following features and/or steps, which alone or in any combination may comprise patentable subject matter.

In accordance with the teachings disclosed herein, embodiments related to a vertically rotating grooming attachment brush and method of use are disclosed.

Embodiments of the present invention can remove biofouling, which be, for example, slime-like biofilms and incipient fouling, from surfaces of marine and freshwater structures such as, for example, surfaces of ship hulls. The grooming attachment brush comprises a brush hub and an arrangement of grooming and shroud bristles. Vertical rotation of the grooming attachment brush creates a vortical flow in the brush hub which generates a low pressure region in the central area of the brush hub. This low pressure region creates a force that forcefully attracts the grooming attachment brush to the surface to be cleaned, thereby attaching it the surface.

The present method and device of the invention overcome the shortcomings of the prior art by attaching to a surface to be cleaned, such as a ship hull or other surface, with enough force to effectively groom or clean the surface of unwanted materials such as biofouling. The present method and device of the invention may be utilized to clean surfaces other than surfaces of ships, and to remove unwanted materials therefrom.

In an embodiment, the grooming attachment brush comprises a brush hub having a tuft attachment surface, a row of grooming bristles extending from the tuft attachment surface and positioned at or near a periphery of the brush hub, and a row of shroud bristles extending from the tuft attachment surface and positioned along and interior to the row of grooming bristles, in which the grooming bristles extend from the tuft attachment surface further than the shroud bristles extend from the tuft attachment surface.

In an alternate embodiment, the grooming attachment brush comprises a brush hub having a tuft attachment surface, a row of shroud bristles extending from the brush hub and positioned at or near a periphery of the brush hub, and a row of grooming bristles extending from the brush hub and positioned along the interior of the row of grooming bristles, in which the grooming bristles extend from the tuft attachment surface further than the shroud bristles extend from the tuft attachment surface.

In yet a further alternate embodiment, the grooming attachment brush comprises a brush hub having a tuft attachment surface and a row of shroud bristles and grooming bristles extending from the brush hub and positioned at or near a periphery of the brush hub, wherein the grooming bristles extend from the tuft attachment surface further than the shroud bristles extend from the tuft attachment surface.

In yet a further alternate embodiment the brush hub is circular in shape.

In yet a further alternate embodiment, the grooming attachment brush further comprises a rigid shroud positioned about an edge of the brush hub, and the shroud bristles extend from the tuft attachment surface further than the shroud extends from the tuft attachment surface.

In a still further alternate embodiment, the grooming attachment brush further comprises one or more shroud bristle tufts positioned near the center of the brush hub in an impeller vein shape.

The method of the invention may comprise providing a surface to be cleaned, providing at least one grooming attachment brush having a row of grooming bristles having tips, the grooming bristles extending from a brush hub and positioned at or near a periphery of brush hub, and a row of shroud bristles having tips, the shroud bristles extending from the brush hub and positioned either along and interior of the row of grooming bristles, or along and exterior to the row of grooming bristles, or in the same row as the grooming bristles, and the at least one grooming attachment brush also having a tuft attachment surface, wherein the grooming bristles extend from the tuft attachment surface further than the shroud bristles extend from the tuft attachment surface; and rotating the at least one grooming attachment brush at a predetermined rotational speed while placing said shroud brush tips against said surface to be cleaned. The method of the invention may utilize any number of grooming attachment brushes.

In an alternate embodiment, the method of the invention may further comprise at least one grooming attachment brush having a plurality of shroud bristle tufts extending from the tuft attachment surface and positioned near the center of the brush hub in an impeller vein shape.

In a still further alternate embodiment, the method of the invention may further be defined as being utilized on the surface of ship having biofouling.

In a still further alternate embodiment, the method of the invention may further be defined as the rotational speed of the at least one grooming attachment brush being greater than 200 rotations per minute or between 200 and 1100 rotations per minute.

In a still further alternate embodiment, the method the invention may further be defined as wherein the at least one grooming attachment brush further comprises a plurality of shroud bristle tufts extending from the tuft attachment surface and positioned near the center of the brush hub in an impeller vein shape.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating the preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:

FIG. 1 is a perspective view of a vertically rotating grooming attachment brush having a grooming bristle tuft and a shroud bristle tuft occupying the same row of bristles according to an embodiment of the present invention.

FIG. 2 is a perspective view of a vertically rotating grooming brush having two rows of bristles—a shroud bristle tuft on an outer row and a grooming bristle tuft on an inner row—according to an embodiment of the present invention.

FIG. 3 is a perspective view of a vertically rotating grooming brush having two rows of bristles—a shroud bristle tuft on an inner row and a grooming bristle tuft on an outer row—according to an embodiment of the present invention.

FIG. 4 is a perspective view of a vertically rotating grooming brush having a grooming bristle tuft and a shroud bristle tuft occupying the same row of bristles and a rigid shroud attached to the brush hub according to an embodiment of the present invention.

FIG. 5 is a perspective view of a vertically rotating grooming brush having a grooming bristle tuft and a shroud bristle tuft occupying the same row of bristles and shroud bristle tufts positioned in the center of the hub, mimicking the veins of an impeller according to an embodiment of the present invention.

FIG. 6 is a side elevational view of a vertically rotating grooming brush having a grooming bristle tuft and a shroud bristle tuft occupying the same row of bristles and illustrating the angle of the bristles relative to the surface of the brush hub according to an embodiment of the present invention.

FIG. 7 is a graph illustrating different attachment forces generated by vertically rotating exemplary vertically rotating grooming brushes of various diameters (given in centimeters) at various speeds.

FIG. 8 is a table illustrating the attachment forces (given in attachment force per unit power input (N/W)) generated by vertically rotating exemplary vertically rotating grooming brushes having a shroud of various heights at various speeds.

FIG. 9 is a graph illustrating the distribution of the low pressure region developed by vertically rotating a vertically rotating grooming brush held at different heights above the test surface (given in centimeters), wherein the y-axis represents the negative pressure region relative to ambient water pressure of the same depth and the x-axis represents the distance from the center of the brush in which the measurement was taken.

FIG. 10 is graph illustrating the grooming efficiency of vertically rotating grooming brushes with different features as described on the x-axis (brush name/rpm). The CrenX brushes had grooming and shroud bristles on the same row, with X being the angle of the bristles relative to the surface of the brush hub. The SH Out brushes comprised shroud bristles on an outside row and grooming brushes on an inside row. The SH In brushes had the shroud bristles on an inside row and grooming brushes on an outside row.

DETAILED DESCRIPTION OF THE INVENTION

The following documentation provides a detailed description of the various embodiments of the invention.

A detailed description of the embodiments for a vertically rotating grooming attachment brush will now be presented with reference to FIGS. 1-10. One of skill in the art will recognize that these embodiments are not intended to be limitations on the scope, and that modifications are possible without departing from the spirit thereof. In certain instances, well-known methods, procedures, components, and circuits have not been described in detail.

Embodiments of the present invention can remove slime-like biofilms and incipient fouling from marine and freshwater structures, such as ship hulls. Such structures may be coated with antifouling paint. Embodiments of the present invention can also be used on offshore floating structures and fixed structures, sides of aquaria and any other submerged or partially submerged structure that have unwanted accumulations of biofouling, organic and inorganic matter.

Embodiments of a grooming attachment brush comprise a brush hub and an arrangement of grooming and shroud bristles. As illustrated in FIGS. 1-6, embodiments of the grooming attachment brush include bristle tufts that extend from the brush hub. The bristles are arranged in a manner that generates vortical fluid flow when the grooming attachment brush is vertically rotated and placed against the surface to be cleaned. In an embodiment of the method of the invention, the grooming attachment brush is vertically rotated and placed against the surface to be cleaned such that tips of the shroud bristles are in contact with the surface to be cleaned. The brush geometry and speed of rotation causes the development of a low pressure region within the brush cavity (the central area of the brush hub). This low pressure cell results in a force that attracts (and attaches) the grooming attachment brush to the surface of the structure to be groomed or cleaned. The cleaning force developed between the brush and the surface is a function of the bristles' length, diameter and modulus, the speed of rotation of the brush hub, the bristles' normal forces and attraction forces developed by the low pressure cell and any wheels, castors or rollers that may be used to control the distance the brush head attachment is set off from the surface.

As shown in FIGS. 1-6, a grooming attachment brush comprises a brush hub and a combination of grooming bristles and shroud bristles that are arranged circumferentially at or near the outer rim of a brush hub. The embodiment shown in FIG. 1 illustrates grooming bristle tuft 1 and shroud bristle tuft 2 occupying the same row of bristles on the brush hub 6. The embodiment shown in FIG. 2 illustrates the grooming bristle tuft 1 occupying an inner row and the shroud bristle tuft 2 occupying an outer row. In FIG. 3, the grooming bristle tuft 1 occupies an outer row, while the shroud bristle tuft 2 occupies the inner row. In the embodiment shown in FIG. 4, a rigid shroud 3, or skirt, is attached to the brush hub 6. The embodiment shown in FIG. 5 illustrates shroud bristle tufts 4 positioned in the center area of the brush hub 6. These shroud bristle tufts mimic the veins of an impeller. The embodiment shown in FIG. 6 illustrates the angle 5 of the bristles relative to the surface of the brush hub 6. In the exemplary embodiments shown in FIGS. 1-6, bristles comprising grooming bristle tuft 1 may extend from tuft attachment surface 7 further than bristles comprising shroud bristle tuft 2 extend from tuft attachment surface 7.

Vertical rotation of the grooming attachment brush can be provided by, for example, at least one electric motor or at least one hydraulic motor, or a combination of electric and hydraulic motors.

The brush hub can take on a variety of shapes. For example, the general shape of the brush hub can be circular as shown in FIGS. 1-6. Alternatively, the general shape of the brush hub can be oval or rectangular. Regardless of general shape of the brush hub, the thickness of the brush hub can be uniform or vary. For example, the brush hub can be generally planar. A generally planer brush hub can have an inset portion or multiple inset portions towards the center of the brush hub. A circular and generally planar brush hub with multiple circular inset portions is illustrated in FIGS. 1-6. Alternatively, the brush hub can be generally convex or concave in structure.

Different material properties of the bristle tufts, such as, for example modulus, hardness, creep, fatigue strength and water absorption, and different physical properties, such as, for example diameter, length, and number of bristles, can be utilized to aid in the generation of the low pressure region created in the brush hub and/or the efficiency of grooming. The arrangement of the bristle tufts, such as, for example, the relative location of the bristles to each other, the angle of the bristles and the height of the bristle tufts above the fixed surface can also be utilized to aid in the generation of the low pressure region created in the brush hub and/or the efficiency of grooming.

Embodiments of the present invention, such as that illustrated in FIG. 4, include a rigid or elastomeric shroud, or skirt, along the periphery of the brush hub. A shroud or skirt can decrease viscous brush drag and increase attachment of a grooming attachment brush by isolating the low pressure region created at the center of the device. The shroud or skirt can be permanently or detachably affixed to the brush hub. It can be made of rigid material. Alternatively, it can be made of compliant/flexible material. The shroud or skirt can also be made of a one or more shroud bristle tufts. If the shroud or skirt is made of one or more shroud bristle tufts, such shroud bristle tuft(s) can be in the same row of bristles as the grooming bristle tufts, as illustrated in the example shown in FIG. 1, or can be in separate rows, as illustrated in the exemplary embodiments shown in FIGS. 2 and 3.

The brushes tested for this method contained bristle tuft dimensions and arrangement selected to achieve both grooming and attachment. Bristles were made from commercially available plastics (polypropylene, nylon, polyester, delrin, etc) and ranged in bristle diameter from 0.3-0.5 mm and a bristle length from 15-35 mm. The tuft diameters ranged from 3.3-4.0 mm. These dimensions were chosen for the purpose of grooming biofilms and incipient foulers, however, the invention relates to brushes, bristles and tufts that maybe used to clean the underwater surfaces of ships, boats or structures. Brushes were also tested that incorporated the use of shrouded bristles. These shorter, stiffer bristles are used to isolate the created low pressure region in the center of the brush cavity by creating a semi-impermeable wall around the brush. The shroud bristle tufts may also control the distance between the brush hub and the surface to be cleaned when the tips of the shroud bristles are in contact with the surface to be cleaned, hence preventing the brush hub from bottoming out on the surface to be cleaned and thereby causing damage.

The brushes described herein were tested in a laboratory facility to determine attachment efficiency, and were field tested for grooming optimization. It was found that the attachment forces generated are a function of both diameter and rotational speed. Measured data is shown in FIG. 7 and visually describes the increasing trend of attachment force generated with an increase in both brush velocity and brush diameter. The brush velocity is presented as tip speed in order to compare different diameter brushes. The exemplary tip speeds tested at approximately 1.2-3.4 m/s were equivalent to 200-1100 rpm. The rotational speed of the brushes can be varied according to the application of the grooming. More tenacious fouling will require higher speeds for removal. The higher rotational speed will increase attachment force and the forces generated at the bristle tip. Larger diameter brushes will generate more attachment force and use greater power.

The efficiency of the grooming attachment brush can be increased by the incorporation of a shroud. Attachment force generated by a brush with a shroud maybe increased by about as much as 30%, compared to forces generated by a brush without a shroud. FIG. 8 shows the increase in attachment with an increase in shroud height. Depending on the stiffness to the bristle tufts, rotational speed, diameter of the brush hub, and the incorporation of a shroud, the grooming attachment brush can be implemented in a wide variety of cleaning activities.

The grooming attachment brush generates a low pressure region by creating a flow that is vortical in nature. A rotational flow is established as well as a vortical flow in the center of the brush hub. The vortical flow is contained within the brush cavity by the incorporation of the shroud bristle tufts and the rigid shroud addition. This isolated flow acts similarly to a tornado and causes a low pressure region to form that causes the brush to adhere the surface of the structure being cleaned. FIG. 9 shows the pressure distribution inside of a brush cavity and illustrates the grooming bristle tufts isolating the low pressure region from the surrounding environment. Because the vortical flow is semi-contained within the brush cavity, the attachment force generated is more energy efficient than a traditional “open” pump system. Brush parameters can be varied based on the forces required to groom or clean a surface. FIG. 10 shows the results from a grooming study, and demonstrates the relationship between brush velocity and the efficiency of fouling removed.

The grooming frequency associated with a grooming attachment brush is based on several factors, such as site location, water temperature, salinity, nutrient concentration, and time of year. The grooming attachment brush can proactively remove biofilms and incipient fouling, so it can be used when such foulers are found on immersed structures.

A plurality of grooming attachment brushes can be coupled together to increase the surface area to be cleaned. A grooming tool system can be designed to fit the grooming application, and attachment needed for any substrate that requires the removal of silt, slimes and incipient fouling. An exemplary grooming tool system can comprise a great train, sprocket, chain, or belt drive system coupled to a single motor. The system can provide for control and monitoring of the rotational speed of the brushes. An exemplary grooming tool system can have each brush controlled by independent motors. Embodiments of the grooming tool system can be mounted to an underwater remote/autonomous vehicle.

Embodiments of the present invention can operate without the need for an open impeller or magnet which allows the vehicle design to be smaller and more energy efficient.

Having now described the invention, the construction, the operation and use of preferred embodiments thereof, and the advantageous new and useful results obtained thereby, the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

Although a detailed description as provided in the attachments contains many specifics for the purposes of illustration, anyone of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the preferred embodiments of the invention are set forth without any loss of generality to, and without imposing limitations upon, the claimed invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, and not merely by the preferred examples or embodiments given. 

What is claimed is:
 1. A grooming attachment brush, comprising: a brush hub having a tuft attachment surface; a row of grooming bristles extending from said tuft attachment surface and positioned at or near a periphery of said brush hub; and a row of shroud bristles extending from said tuft attachment surface and positioned along and interior to the row of grooming bristles; wherein said grooming bristles extend from said tuft attachment surface further than said shroud bristles extend from said tuft attachment surface.
 2. The grooming attachment brush of claim 1, wherein the brush hub is circular in shape.
 3. The grooming attachment brush of claim 1, further comprising a rigid shroud positioned about the edge of the brush hub, wherein said shroud bristles extend from said tuft attachment surface further than said shroud extends from said tuft attachment surface.
 4. The grooming attachment brush of claim 1, further comprising a plurality of shroud bristle tufts positioned near a center of the brush hub in an impeller vein shape.
 5. A grooming attachment brush comprising: a brush hub having a tuft attachment surface; a row of shroud bristles extending from the brush hub and positioned at or near a periphery of said brush hub; a row of grooming bristles extending from the brush hub and positioned along the interior of the row of grooming bristles; wherein said grooming tufts extend from said tuft attachment surface further than said shroud tufts extend from said tuft attachment surface.
 6. The grooming attachment brush of claim 5, wherein the brush hub is circular in shape.
 7. The grooming attachment brush of claim 5, further comprising a rigid shroud positioned about the edge of the brush hub, wherein said shroud bristles extend from said tuft attachment surface further than said shroud extends from said tuft attachment surface.
 8. The grooming attachment brush of claim 5, further comprising a plurality of shroud bristle tufts extending from said tuft attachment surface and positioned near a center of the brush hub in an impeller vein shape.
 9. A grooming attachment brush comprising: a brush hub having a tuft attachment surface; and a row of shroud bristles and grooming bristles extending from said brush hub and positioned at or near a periphery of said brush hub; wherein said grooming bristles extend from said tuft attachment surface further than said shroud bristles extend from said tuft attachment surface.
 10. The grooming attachment brush of claim 9, wherein the brush hub is circular in shape.
 11. The grooming attachment brush of claim 9, further comprising a rigid shroud positioned about the edge of the brush hub, wherein said shroud bristles extend from said tuft attachment surface further than said shroud extends from said tuft attachment surface.
 12. The grooming attachment brush of claim 9, further comprising a plurality of shroud bristle tufts extending from said tuft attachment surface and positioned near a center of the brush hub in an impeller vein shape.
 13. A method for cleaning a surface, comprising: providing a surface to be cleaned: providing at least one grooming attachment brush, wherein said at least one grooming attachment brush comprises: a brush hub having a tuft attachment surface; a row of grooming bristles, said grooming bristles extending from said brush hub and positioned at or near a periphery of said brush hub; and a row of shroud bristles having tips, said shroud bristles extending from said brush hub and positioned either along and interior to the row of grooming bristles, or along and exterior to the row of grooming bristles, or in the same row as the grooming bristles; and wherein said grooming bristles extend from said tuft attachment surface further than said shroud bristles extend from said tuft attachment surface; and rotating said at least one grooming attachment brush at a predetermined rotational speed while placing said shroud brush tips against said surface to be cleaned.
 14. The method of claim 13, wherein said at least one grooming attachment brush further comprises a plurality of shroud bristle tufts extending from said tuft attachment surface and positioned near a center of said brush hub in an impeller vein shape.
 15. The method of claim 13, wherein said surface to be cleaned is further defined as a surface of a hull of a ship, said surface having biofouling.
 16. The method of claim 13, wherein said rotational speed is further defined as being greater than 200 rotations per minute.
 17. The method of claim 13, wherein said rotational speed is between 200 and 1100 rotations per minute.
 18. The method of claim 15, wherein said at least one grooming attachment brush further comprises a plurality of shroud bristle tufts extending from said tuft attachment surface and positioned near a center of the brush hub in an impeller vein shape.
 19. The method of claim 16, wherein said at least one grooming attachment brush further comprises a plurality of shroud bristle tufts extending from said tuft attachment surface and positioned near a center of the brush hub in an impeller vein shape.
 20. The method of claim 17, wherein said at least one grooming attachment brush further comprises a plurality of shroud bristle tufts extending from said tuft attachment surface and positioned near a center of the brush hub in an impeller vein shape. 